/* Copyright  2009
   @Author
   Richard Changde Yin            e-mail yinchangde@hotmail.com

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

/**
 * @filename: rb_tree.h
 */

#ifndef __RB_TREE_H__
#define __RB_TREE_H__
#ifdef	__cplusplus
extern "C" {
#endif

#include <base.h>   /* get 'enum ha_rkey_function' */
#include <global.h>

#include <my_alloc.h>
#define BLACK   1
#define RED     0
#define DEFAULT_ALLOC_SIZE 8192
#define DEFAULT_ALIGN_SIZE 8192

/* Worst case tree is half full. This gives use 2^(MAX_TREE_HEIGHT/2) leafs */
#define MAX_TREE_HEIGHT 64

#define ELEMENT_KEY(tree,element)\
(tree->offset_to_key ? (void*)((unsigned char*) element+tree->offset_to_key) :\
                    *((void**) (element+1)))

#define tree_set_pointer(element,ptr) *((unsigned char **) (element+1))=((unsigned char*) (ptr))

#define TREE_NO_DUPS 1

typedef enum { left_root_right,
               right_root_left
              } TREE_WALK;
typedef uint32_t element_count;
typedef int (*tree_walk_action)(void *,element_count,void *);

typedef enum { free_init,
               free_free,
               free_end }
              TREE_FREE;
typedef void (*tree_element_free)(void*, TREE_FREE, void *);

typedef struct st_tree_element {
  struct st_tree_element *left;
  struct st_tree_element *right;
  uint32_t count:31,
           colour:1;        /* black is marked as 1 */
} TREE_ELEMENT;

#define ELEMENT_CHILD(element, offs) (*(TREE_ELEMENT**)((char*)element + offs))

typedef struct st_tree {
  TREE_ELEMENT *root,null_element;
  TREE_ELEMENT **parents[MAX_TREE_HEIGHT];
  uint32_t offset_to_key,elements_in_tree,size_of_element;
  uint32_t memory_limit, allocated;
  qsort_cmp2 compare;
  void *custom_arg;
  MEM_ROOT mem_root;
  bool  with_delete;
  tree_element_free free;
  uint32_t flag;
} TREE;

  /* Functions on whole tree */
void init_tree(TREE *tree, uint32_t default_alloc_size,
               uint32_t memory_limit,
               int size, qsort_cmp2 compare, bool with_delete,
               tree_element_free free_element, void *custom_arg);
void delete_tree(TREE*);

  /* similar to delete tree, except we do not free() blocks in mem_root
   */
void reset_tree (TREE*);

#define is_tree_inited(tree) ((tree)->root != 0)

/* Functions on leafs */
TREE_ELEMENT *tree_insert(TREE *tree,void *key,
                          uint32_t key_size,
                          void *custom_arg);
void *         tree_search(TREE *tree, void *key, void *custom_arg);
int   tree_walk  (TREE *tree,tree_walk_action action,
                void *argument, TREE_WALK visit);
int   tree_delete(TREE *tree, void *key, uint32_t key_size, void *custom_arg);
void *tree_search_key(TREE *tree, const void *key,
                      TREE_ELEMENT **parents, TREE_ELEMENT ***last_pos,
                      enum ha_rkey_function flag, void *custom_arg);
void *tree_search_edge(TREE *tree, TREE_ELEMENT **parents,
                        TREE_ELEMENT ***last_pos, int child_offs);
void *tree_search_next(TREE *tree, TREE_ELEMENT ***last_pos, int l_offs,
                       int r_offs);
ha_rows tree_record_pos(TREE *tree, const void *key,
                        enum ha_rkey_function search_flag,
                        void *custom_arg);

#define TREE_ELEMENT_EXTRA_SIZE (sizeof(TREE_ELEMENT) + sizeof(void*))

#ifdef __cplusplus
}
#endif
#endif//__RB_TREE_H__
